868 Transactions of the Societij. 



fiat : foot stout, long ; toe apparently single, small, acute. Length, 

 extended, 1/350 in.* Lacustrine. 



This seems the smallest of the genus ; smaller than emarginata, or 

 than triptera, which latter was in sight at the same time, for comparison. 

 It is very transparent and colourless, the viscera only just discernible ; 

 the trophi, though working, were but shadowy lines. The extremity of 

 the lorica is neither pointed, nor sinuate, but evenly round : its over- 

 hanging margins are remarkable, recalhng Notholca scapha. There 

 are two clear colourless globules at the very front, remote from each 

 other, probably eyes. The frontal hook is carried rather close to the 

 front, and seems incapable of independent motion ; it is visible in a dorsal 

 view, as a line parallel to the front. Two minute air-bubbles were in the 

 alimentary canal of the individual examined ; but no particles, nor stain, 

 of food, though the tiny creature was industriously picking all the. time 

 it was under observation, — an hour or more. It was active and restless, 

 creeping about the floccose, but rarely swimming, and then laboriously. 

 A single specimen occurred in a phial of Utricularia sent by Mr. W. B. 

 Hood, from the middle of Ireland. (Fig. 17.) 



18. Dispinthera, gen. nov., Fam. Coluridse. Gen. Char. — Body sub- 

 cylindric, inclosed, in part, within a lorica open in front and in rear, 

 apparently cleft down the venter : head and foot habitually protruded : 

 head distinct, protected by horny plates, but without a frontal hook : 

 two cervical eyes. 



D. capsa. Lorica in most parts soft and flexible : foot stout ; toes 

 two, furcate, thick, straight, tapering, acute. Length 1/250 in. 

 Lacustrine. 



This apparently new form I found in the sediment of water dipped 

 by Mr. Bolton from " ditch No. 2," in Sutton Park, Birmingham, crowded 

 with fine Desmidiese. The facies strikes one as very pecuHar, and 

 dijEficult to explain. The front is capable of much protrusion, in a conical 

 form, where a globose tubercle is visible, but only occasionally ; and a 

 similar one, but more constant, on the occiput (or rather crown of the 

 head), just below the point of the occipital sheath. The lorica is 

 discernible chiefly about the head ; it there projects into several points, 

 which seem very flexible, but constant. When the head is far retracted 

 (which is seldom), an array of spears is lelt bristling up. Now and 

 then, at the pectus, the integument is seen to fall into a flap, or hanging 

 lip, to be presently withdrawn. The principal shield protects the back 

 of the head, but does not form an arching hood, or frontal hook. The 

 trophi, in several good views, seemed of the pattern (fig. 39 of my paper 

 •' On Manducatory Organs," Phil. Trans. 1856) ; assigned to Notomm. 

 gihba. The whole facies recalls one of the smaller Notommatse ; yet the 

 two well-defined eyes remove it from them ; besides the manifest lorica. 

 It seems to approach the marine genus Mytilia, but not very close. 



Only a single specimen occurred, in June. It was active and busy, 

 constantly turning and wheeling about, but little given to locomotion. 



* The figures in the plates are not drawn to one scale ; if they were, this would be not 

 one-fourth as long as No. 13 on the left of it. Each figure is drawn as the containing 

 area will permit, the object being to sliow as much structural detail as possible. 



